﻿#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
using namespace std;

// MyUnorderedSet.h
namespace zyb
{
	template<class K, class Hash = HashFunc<K>>
	class unordered_set
	{
		struct SetKeyOfT
		{
			const K& operator()(const K& key)
			{
				return key;
			}
		};
	public:
		bool insert(const K& key)
		{
			return _ht.Insert(key);
		}
	private:
		hash_bucket::HashTable<K, K, SetKeyOfT, Hash> _ht;
	};
}

// MyUnorderedMap.h
namespace zyb
{
	template<class K, class V, class Hash = HashFunc<K>>
	class unordered_map
	{
		struct MapKeyOfT
		{
			const K& operator()(const pair<K, V>& kv)
			{
				return kv.first;
			}
		};
	public:
		bool insert(const pair<K, V>& kv)
		{
			return _ht.Insert(kv);
		}
	private:
		hash_bucket::HashTable<K, pair<K, V>, MapKeyOfT, Hash> _ht;
	};
}

// HashTable.h
template<class K>
struct HashFunc
{
	size_t operator()(const K& key)
	{
		return (size_t)key;
	}
};

namespace hash_bucket
{
	template<class T>
	struct HashNode
	{
		T _data;
		HashNode<T>* _next;
		HashNode(const T& data)
			:_data(data)
			, _next(nullptr)
		{}
	};
	// 实现步骤：
	// 1、实现哈希表
	// 2、封装unordered_map和unordered_set的框架 解决KeyOfT
	// 3、iterator
	// 4、const_iterator
	// 5、key不支持修改的问题
	// 6、operator[]
	template<class K, class T, class KeyOfT, class Hash>
	class HashTable
	{
		typedef HashNode<T> Node;
		inline unsigned long __stl_next_prime(unsigned long n)
		{
			static const int __stl_num_primes = 28;
			static const unsigned long __stl_prime_list[__stl_num_primes] =
			{
			53, 97, 193, 389, 769,
			1543, 3079, 6151, 12289, 24593,
			49157, 98317, 196613, 393241, 786433,
			1572869, 3145739, 6291469, 12582917, 25165843,
			50331653, 100663319, 201326611, 402653189, 805306457,
			1610612741, 3221225473, 4294967291
			};
			const unsigned long* first = __stl_prime_list;
			const unsigned long* last = __stl_prime_list + __stl_num_primes;
			const unsigned long* pos = lower_bound(first, last, n);
			return pos == last ? *(last - 1) : *pos;
		}
	public:
		HashTable()
		{
			_tables.resize(__stl_next_prime(_tables.size()), nullptr);
		}
		~HashTable()
		{
			// 依次把每个桶释放
			for (size_t i = 0; i < _tables.size(); i++)
			{
				Node* cur = _tables[i];
				while (cur)
				{
					Node* next = cur->_next;
					delete cur;
					cur = next;
				}
				_tables[i] = nullptr;
			}
		}
		bool Insert(const T& data)
		{
			KeyOfT kot;
			if (Find(kot(data)))
				return false;
			Hash hs;
			size_t hashi = hs(kot(data)) % _tables.size();
			// 负载因⼦==1扩容
			if (_n == _tables.size())
			{
				vector<Node*> newtables(__stl_next_prime(_tables.size()),
					nullptr);
				for (size_t i = 0; i < _tables.size(); i++)
				{
					Node* cur = _tables[i];
					while (cur)
					{
						Node* next = cur->_next;
						// 旧表中结点，挪动新表重新映射的位置
						size_t hashi = hs(kot(cur->_data)) % newtables.size();
						// 头插到新表
						cur->_next = newtables[hashi];
						newtables[hashi] = cur;
						cur = next;
					}
					_tables[i] = nullptr;
				}
				_tables.swap(newtables);
			}
			// 头插
			Node* newnode = new Node(data);
			newnode->_next = _tables[hashi];
			_tables[hashi] = newnode;
			++_n;
			return true;
		}
	private:
		vector<Node*> _tables; // 指针数组
		size_t _n = 0; // 表中存储数据个数
	};
}

template <class Value, class Key, class HashFcn,
	class ExtractKey, class EqualKey, class Alloc>
struct __hashtable_iterator {
	typedef hashtable<Value, Key, HashFcn, ExtractKey, EqualKey, Alloc>
		hashtable;
	typedef __hashtable_iterator<Value, Key, HashFcn,
		ExtractKey, EqualKey, Alloc>
		iterator;
	typedef __hashtable_const_iterator<Value, Key, HashFcn,
		ExtractKey, EqualKey, Alloc>
		const_iterator;
	typedef __hashtable_node<Value> node;
	typedef forward_iterator_tag iterator_category;
	typedef Value value_type;
	node* cur;
	hashtable* ht;
	__hashtable_iterator(node* n, hashtable* tab) : cur(n), ht(tab) {}
	__hashtable_iterator() {}
	reference operator*() const { return cur->val; }
#ifndef __SGI_STL_NO_ARROW_OPERATOR
	pointer operator->() const { return &(operator*()); }
#endif /* __SGI_STL_NO_ARROW_OPERATOR */
	iterator& operator++();
	iterator operator++(int);
	bool operator==(const iterator& it) const { return cur == it.cur; }
	bool operator!=(const iterator& it) const { return cur != it.cur; }
};
template <class V, class K, class HF, class ExK, class EqK, class A>
__hashtable_iterator<V, K, HF, ExK, EqK, A>&
__hashtable_iterator<V, K, HF, ExK, EqK, A>::operator++()
{
	const node* old = cur;
	cur = cur->next;
	if (!cur) {
		size_type bucket = ht->bkt_num(old->val);
		while (!cur && ++bucket < ht->buckets.size())
			cur = ht->buckets[bucket];
	}
	return *this;
}

//---------------------------------------------------------------------------------
// MyUnorderedSet.h
namespace zyb
{
	template<class K, class Hash = HashFunc<K>>
	class unordered_set
	{
		struct SetKeyOfT
		{
			const K& operator()(const K& key)
			{
				return key;
			}
		};
	public:
		typedef typename hash_bucket::HashTable<K, const K, SetKeyOfT,
			Hash>::Iterator iterator;
		typedef typename hash_bucket::HashTable<K, const K, SetKeyOfT,
			Hash>::ConstIterator const_iterator;
		iterator begin()
		{
			return _ht.Begin();
		}
		iterator end()
		{
			return _ht.End();
		}
		const_iterator begin() const
		{
			return _ht.Begin();
		}
		const_iterator end() const
		{
			return _ht.End();
		}
		pair<iterator, bool> insert(const K & key)
		{
			return _ht.Insert(key);
		}
		iterator Find(const K & key)
		{
			return _ht.Find(key);
		}
		bool Erase(const K & key)
		{
			return _ht.Erase(key);
		}
	private:
		hash_bucket::HashTable<K, const K, SetKeyOfT, Hash> _ht;
	};
}

// MyUnorderedMap.h
namespace zyb
{
	template<class K, class V, class Hash = HashFunc<K>>
	class unordered_map
	{
		struct MapKeyOfT
		{
			const K& operator()(const pair<K, V>& kv)
			{
				return kv.first;
			}
		};
	public:
		typedef typename hash_bucket::HashTable<K, pair<const K, V>,
			MapKeyOfT, Hash>::Iterator iterator;
		typedef typename hash_bucket::HashTable<K, pair<const K, V>,
			MapKeyOfT, Hash>::ConstIterator const_iterator;
		iterator begin()
		{
			return _ht.Begin();
		}
		iterator end()
		{
			return _ht.End();
		}
		const_iterator begin() const
		{
			return _ht.Begin();
		}
		const_iterator end() const
		{
			return _ht.End();
		}
		pair<iterator, bool> insert(const pair<K, V>& kv)
		{
			return _ht.Insert(kv);
		}
		V& operator[](const K& key)
		{
			pair<iterator, bool> ret = _ht.Insert(make_pair(key, V()));
			return ret.first->second;
		}
		iterator Find(const K& key)
		{
			return _ht.Find(key);
		}
		bool Erase(const K& key)
		{
			return _ht.Erase(key);
		}
	private:
		hash_bucket::HashTable<K, pair<const K, V>, MapKeyOfT, Hash> _ht;
	};
}

// HashTable.h
template<class K>
struct HashFunc
{
	size_t operator()(const K& key)
	{
		return (size_t)key;
	}
};
// 特化
template<>
struct HashFunc<string>
{
	size_t operator()(const string& key)
	{
		size_t hash = 0;
		for (auto e : key)
		{
			hash *= 131;
			hash += e;
		}
		return hash;
	}
};
namespace hash_bucket
{
	template<class T>
	struct HashNode
	{
		T _data;
		HashNode<T>* _next;
		HashNode(const T& data)
			:_data(data)
			, _next(nullptr)
		{}
	};
	// 前置声明
	template<class K, class T, class KeyOfT, class Hash>
	class HashTable;
	template<class K, class T, class Ptr, class Ref, class KeyOfT, class Hash>
	struct HTIterator
	{
		typedef HashNode<T> Node;
		typedef HTIterator<K, T, Ptr, Ref, KeyOfT, Hash> Self;
		Node* _node;
		const HashTable<K, T, KeyOfT, Hash>* _pht;
		HTIterator(Node* node, const HashTable<K, T, KeyOfT, Hash>* pht)
			:_node(node)
			, _pht(pht)
		{}
		Ref operator*()
		{
			return _node->_data;
		}
		Ptr operator->()
		{
			return &_node->_data;
		}
		bool operator!=(const Self& s)
		{
			return _node != s._node;
		}
		Self& operator++()
		{
			if (_node->_next)
			{
				// 当前桶还有节点
				_node = _node->_next;
			}
			else
			{
				// 当前桶走完了，找下一个不为空的桶
				KeyOfT kot;
				Hash hs;
				size_t hashi = hs(kot(_node->_data)) % _pht -> _tables.size();
				++hashi;
				while (hashi < _pht->_tables.size())
				{
					if (_pht->_tables[hashi])
					{
						break;
					}
					++hashi;
				}

				if (hashi == _pht->_tables.size())
				{
					_node = nullptr; // end()
				}
				else
				{
					_node = _pht->_tables[hashi];
				}
			}
			return *this;
		}
	};
	template<class K, class T, class KeyOfT, class Hash>
	class HashTable
	{
		// 友元声明
		template<class K, class T, class Ptr, class Ref, class KeyOfT, class Hash>
		friend struct HTIterator;

		typedef HashNode<T> Node;
	public:
		typedef HTIterator<K, T, T*, T&, KeyOfT, Hash> Iterator;
		typedef HTIterator<K, T, const T*, const T&, KeyOfT, Hash> ConstIterator;

		Iterator Begin()
		{
			if (_n == 0)
				return End();
			for (size_t i = 0; i < _tables.size(); i++)
			{
				Node* cur = _tables[i];
				if (cur)
				{
					return Iterator(cur, this);
				}
			}
			return End();
		}

		Iterator End()
		{
			return Iterator(nullptr, this);
		}

		ConstIterator Begin() const
		{
			if (_n == 0)
				return End();
			for (size_t i = 0; i < _tables.size(); i++)
			{
				Node* cur = _tables[i];
				if (cur)
				{
					return ConstIterator(cur, this);
				}
			}
			return End();
		}

		ConstIterator End() const
		{
			return ConstIterator(nullptr, this);
		}

		inline unsigned long __stl_next_prime(unsigned long n)
		{
			static const int __stl_num_primes = 28;
			static const unsigned long __stl_prime_list[__stl_num_primes] =
			{
				53, 97, 193, 389, 769,
				1543, 3079, 6151, 12289, 24593,
				49157, 98317, 196613, 393241, 786433,
				1572869, 3145739, 6291469, 12582917, 25165843,
				50331653, 100663319, 201326611, 402653189, 805306457,
				1610612741, 3221225473, 4294967291
			};
			const unsigned long* first = __stl_prime_list;
			const unsigned long* last = __stl_prime_list +
				__stl_num_primes;
			const unsigned long* pos = lower_bound(first, last, n);
			return pos == last ? *(last - 1) : *pos;
		}
		HashTable()
		{
			_tables.resize(__stl_next_prime(_tables.size()), nullptr);
		}
		~HashTable()
		{
			// 依次把每个桶释放
			for (size_t i = 0; i < _tables.size(); i++)
			{
				Node* cur = _tables[i];
				while (cur)
				{
					Node* next = cur->_next;
					delete cur;
					cur = next;
				}
				_tables[i] = nullptr;
			}
		}
		pair<Iterator, bool> Insert(const T& data)
		{
			KeyOfT kot;
			Iterator it = Find(kot(data));
			if (it != End())
				return make_pair(it, false);
			Hash hs;
			size_t hashi = hs(kot(data)) % _tables.size();
			// 负载因子 ==1扩容
			if (_n == _tables.size())
			{
				vector<Node*>
					newtables(__stl_next_prime(_tables.size() + 1), nullptr);
				for (size_t i = 0; i < _tables.size(); i++)
				{
					Node* cur = _tables[i];
					while (cur)
					{
						Node* next = cur->_next;
						// 旧表中节点，挪动新表重新映射的位置
						size_t hashi = hs(kot(cur->_data)) %
							newtables.size();
						// 头插到新表
						cur->_next = newtables[hashi];
						newtables[hashi] = cur;
						cur = next;
					}
					_tables[i] = nullptr;
				}
				_tables.swap(newtables);
			}
			// 头插
			Node* newnode = new Node(data);
			newnode->_next = _tables[hashi];
			_tables[hashi] = newnode;
			++_n;
			return make_pair(Iterator(newnode, this), true);
		}
		Iterator Find(const K& key)
		{
			KeyOfT kot;
			Hash hs;
			size_t hashi = hs(key) % _tables.size();
			Node* cur = _tables[hashi];
			while (cur)
			{
				if (kot(cur->_data) == key)
				{
					return Iterator(cur, this);
				}
				cur = cur->_next;
			}
			return End();
		}
		bool Erase(const K& key)
		{
			KeyOfT kot;
			Hash hs;
			size_t hashi = hs(key) % _tables.size();
			Node* prev = nullptr;
			Node* cur = _tables[hashi];
			while (cur)
			{
				if (kot(cur->_data) == key)
				{
					if (prev == nullptr)
					{
						_tables[hashi] = cur->_next;
					}
					else
					{
						prev->_next = cur->_next;
					}
					delete cur;
					--_n;
					return true;
				}
				prev = cur;
				cur = cur->_next;
			}
			return false;
		}
	private:
		vector<Node*> _tables; // 指针数组
		size_t _n = 0; // 表中存储数据个数
	};
}